Description
Resistance to erythropoietin (EPO) treatment is observed in a considerable proportion of anemic patients with chronic kidney disease. Previous reports suggest that inflammation is one of the major independent predictors of this resistance, and pro-inflammatory cytokines have been shown to inhibit erythropoiesis. The aim of this study was to investigate EPO-induced modification to gene expression in primary cultured leukocytes.; Microarray experiments were performed on ex vivo Peripheral Blood Mononuclear Cells (PBMCs) from pooled ten healthy donors (n=9), primed or not with TNF-alpha, and treated with recombinant human erythropoietin alpha (EPO-alpha). Real-time PCR experiments were used to validate expression of the molecular targets considered most relevant for inflammation.; Data analysis suggested that EPO-alpha treatment mainly modulated genes involved in cell movement and cell-cell interaction in primed PBMCs. Notably, EPO-alpha exerts anti-inflammatory effects inhibiting the expression of pro-inflammatory cytokine IL-8 and its receptor CXCR2; by contrast, EPO-alpha further increases expression of genes relating to promotion of inflammation encoding for IL-1beta and CCL8, and induces de novo synthesis of IL-1alpha, CXCL1 and CXCL5 in primed PBMCs. MAPK p38alpha?reducing activity is involved in modulation of IL-1beta and IL-8 expression.; In conclusion, our findings confirm the anti-inflammatory role for EPO, but also suggest a plausible in vivo scenario, in which the positive correlation found between EPO-resistance and elevated levels of some pro-inflammatory mediators is due to treatment with EPO itself. One future objective will be to perform in vivo measurement of the molecular targets highlighted, in order to identify any additional markers involved in EPO-resistance among hypo-responsive patients.
Overall Design
In this study, we analyzed the expression profiles of pooled blood PBMCs from 10 healthy donors primed or not with TNF-alpha and then treated with EPO-alpha. All RNAs from no stimulated PBMCs were hybridized against RNAs from PBMCs treated with TNF-alpha or TNF-alpha and EPO-alpha. We performed a total of 9 technical replicates.
Curator
RGEDv1